JPH0212247A - Transformed image forming method - Google Patents

Abstract

PURPOSE:To obtain the physical dot gain similar to the physical dot gain of actual printed matter by incorporating a highly water-absorptive resin into a colored photosensitive layer. CONSTITUTION:The highly water-absorptive resin is incorporated into the colored photosensitive layer contg. a photosensitive compsn. and coloring agent. This highly water-absorptive resin absorbs water of several hundred times to several thousand times its own weight and the gel which once swells by absorbing water has the excellent water retaining property to prevent the desorption of the water in spite of exertion of some pressure thereto unlike a sponge and pulp. Said resin is the slightly crosslinked water soluble high polymer when the resin is structurally examined. The dots of fine lines obtd. with the absorption of the moisture in a developing soln. by the highly water- absorptive resin when the image forming material is developed after imagewise exposing swell circumferentially to form the physical dot gain and the transferred image approximate to the actual printed matter is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a colored transfer image forming method used for forming color proofs and the like.

[Conventional technology]

When producing color images, whether in litho, letterplace or gravure, the /%-ftone method is used and requires color-separated halftone dots, positive or negative plates.

In order to save the labor and time of proof printing prior to actual printing, color sheets for color proofing, ie, color proofs, are known in the boat industry.

Regarding the layer structure and image forming method of this color proof,
Various proposals have been made. Color proof transfer methods include (1) a method in which a photosensitive layer containing a coloring material is transferred to a support, and exposure and development are repeated to form an image;
2) A method in which a photosensitive adhesive layer is laminated on a support and a toner is applied after exposure; (3) A method in which a monochromatic image formed on a color sheet is sequentially transferred to an image-receiving layer and then re-transferred to an adherend, etc. There is.

In any case, optical dot gain is produced by covering the image with a polymer coating so that the transferred image approximates the image on the actual printed matter.

[Problem to be solved by the invention]

However, as long as conventional colored photosensitive layer forming materials are used, even if optical dot gain is produced by covering the resulting image with a polymer film, it is essentially different from the physical dot gain of the actual printed matter. You can only get a different texture.

Therefore, the main object of the present invention is to provide a transfer image forming method that can obtain a physical dot gain similar to that of actual printed matter.

[Means to solve the problem]

The above problem is to develop an image forming material having a colored photosensitive layer containing a photosensitive composition and a colorant on a support, after image exposure, to form a colored image, and to transfer this to a transfer material. In the method of forming a transferred image using the colored photosensitive layer, this problem can be solved by containing a highly water-absorbing resin in the colored photosensitive layer.

[Specific structure of the invention]

The present invention will be further explained below.

In the present invention, a superabsorbent resin is contained in the colored photosensitive layer.

As a result, when the image-forming material is developed after imagewise exposure, the superabsorbent resin absorbs water in the developer, causing the resulting halftone dots or thin lines to swell around them, resulting in physical dot gain. Become. Therefore, the transferred image obtained by transfer closely approximates the actual printed matter. Further, the degree of swelling can be controlled by selecting the type of superabsorbent resin, the amount added, etc.

The superabsorbent resin used in the present invention is a gel that absorbs hundreds to thousands of times its own weight in water, and once it absorbs water and swells, unlike sponges and bulbs, it can absorb water even when applied with some pressure. It has excellent water retention properties that prevent water from separating, and its structure is made by slightly crosslinking water-soluble polymers.

Examples of such products include: ■ starch-based starch graft polymerized with acrylate; ■ cellulose-based carboxycellulose graft polymerized with acrylate; ■ synthetic polymer-based acrylic acid/vinyl alcohol copolymers, acrylic acid polymers, etc. Examples include polymers, acrylic acid/acrylamide copolymers, and polyethylene oxide modified products.

Examples of commercially available superabsorbent polymers, including those currently produced by Viloft, are shown in Table 1.

The amount of super absorbent resin added to the colored photosensitive layer is 5 to 5 wt.
% is preferably 10-15-t%. In addition, "Solvent-soluble types such as Sumikagel R-30LJ (manufactured by Sumitomo Chemical Co., Ltd.) are easier to add to the colored photosensitive layer, but in the case of solids, fine particles are preferable. In that case, The particle size is preferably 1 to 20 μm, preferably 10 μm or less.

The colored photosensitive layer containing the photosensitive composition and colorant of the present invention is removed imagewise by imagewise exposure and subsequent development to form a colored image.

This colored photosensitive layer may be one layer or multiple layers, that is, it is sufficient that the coloring agent and the photosensitive composition are contained in any one of the layers. For example, a colored recording layer containing a colorant and a photosensitive composition, a colored layer containing a colorant and not having a photosensitive composition, and a photosensitive layer containing a photosensitive composition and not having a colorant are combined as appropriate to form a laminated structure. It can be done.

The above-mentioned superabsorbent resin is added to the colored recording layer when it is only one layer, and to the colored layer when it consists of two layers, a colored layer and a photosensitive layer.

Since the coloring agent does not have film-forming properties, a binder is used.

As the binder constituting the colored recording layer, a film-forming, solvent-soluble polymer compound that can be dissolved or swelled in a developer is used.

Specific examples of this polymer compound include acrylic acid, methacrylic acid and their alkyl esters or sulfoalkyl esters, phenol resins, polyvinyl butyral,
Polyacrylamide, ethyl cellulose, cellulose acetate/butyrate, vinegar M.

Cellulose derivatives such as cellulose pionate, cellulose acetate, benzyl cellulose, cellulose propionate, other polystyrene, polyvinyl chloride, chlorinated rubber,
polyisobutylene, polybutadiene, polyvinyl acetate,
and copolymers thereof, cellulose acetate, cellulose propionate, cellulose acetate phthalate, and the like.

Dyes and pigments are added as coloring substances to the colored photosensitive layer. In particular, when used for color proofing, pigments and dyes with tones matching the usual colors required, i.e. yellow, magenta, cyan, and black, are required, but in addition, metal powders, white pigments, fluorescent pigments, etc. Zero-order examples, also used, are some of the many pigments and dyes known in the art. (C, 1 means color index.) Victoria Pure Blue (C, I 42595) Auramine 0 (C, I 41000) Cation Brilliant Flavin (C, I Basic 13) Rhodami 76 GcP (C, r 45160) Rhodamine B (C,I 45170) Safranin 0K70:
100 (C, I 50240) Erioglaucine X
(C, 142080) Fast Black HB (
C, I 26150) 11m1201 Lionor Yellow (C, I 21090) Lionor Yellow GRO
(C, I 21090) Shimla Fast Yellow 8
GF (C,I 21105) Benzidine Yellow 4T
-5640 (C, I 21095) Shimla Fast Red 4015 (C, I 12355) Lionor Red 7B4401 (C, 115830) First Gen Blue TGR-L (C, I 74160) Lionor Blue-SM (C, I 26150) Mitsubishi Carbon Black MA-100 Mitsubishi Carbon Black 1130, 140, 1150 The colorant/binder ratio of the colored photosensitive layer used in the present invention is determined by those skilled in the art, taking into account the target optical density and the removability of the colored photosensitive layer to the developer. For example, in the case of dyes, the content is 5% to 7% by weight.
In the case of pigment, the content is suitably 5% to 90% by weight.

In addition, the film thickness of the colored photosensitive layer of the present invention has a target optical density,
It can be determined by a method known to those skilled in the art depending on the type of colorant (dye, pigment, carbon black) used in the colored photosensitive layer and its content, but the thickness of the colored photosensitive layer should be determined as much as possible within the allowable range. The thinner the film, the higher the developing power and the better the image quality.

Furthermore, a photosensitive component is added to this colored photosensitive layer within a range that does not impair film-forming properties. As the photosensitive component that can be added, there is used one that can cause a difference in solubility or swellability in a developer between exposed and unexposed areas upon irradiation with actinic rays. So-called negative-positive type resins, in which the solubility or swelling property in developing solutions decreases in areas exposed to actinic rays, include photocrosslinkable photosensitive resins such as polyvinyl alcohol esterified with cinnamic acid; Examples include diazonium salts, condensates thereof, aromatic amide compounds, and photosensitive resins using photoradical polymerization or photoionic polymerization. On the other hand, naphthoquinone diazide compounds and the like are examples of so-called positive-positive type materials in which the portions exposed to actinic rays have increased solubility or swelling in a developer.

As the support for the photosensitive image forming material used in the present invention, a polyester film, particularly a biaxially oriented polyethylene terephthalate film is preferred in terms of dimensional stability against water and heat, but acetate film, polyvinyl chloride film, and polystyrene film are preferred. , polypropylene films may also be used. Further, these supports may be used as they are, but in order to improve the transferability of the image after image formation, they may be subjected to a release treatment with an appropriate oil-repellent material, or may be provided with an undercoat layer.

Examples of oil-repellent substances include silicone resins, fluororesins, and fluorosurfactants. Alternatively, a polyethylene film or a polypropylene film may be laminated onto a two-wheel stretched polyethylene terephthalate film using an adhesive, or polyethylene or polypropylene may be combined with polyethylene terephthalate using a coextrusion method to form a thin film layer of polyethylene or polypropylene on the polyethylene terephthalate film. By doing so, a mold release treatment can be performed.

Examples of the undercoat layer include alcohol-soluble polyamide, alcohol-soluble nylon, a blend of a partially esterified resin of a copolymer of styrene and maleic anhydride, and methoxymethylated nylon, polyvinyl acetate, polyacrylate, Copolymers of polymethyl methacrylate and acrylate, polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl butylade, cellulose acetate phthalate, methylcellulose, ethylcellulose, cellulose diacetate, cellulose triacetate, polyvinyl alcohol. Examples include those that have weak adhesion to the transparent support.

In order to produce the above-mentioned image-forming material, the above-mentioned colored photosensitive layer-forming material may be dissolved in a suitable solvent and coated on the above-mentioned support.

Examples of solvents include water, methanol, ethanol, acetone, ethyl acetate, methyl cellosolve, ethyl cellosolve, dioxane, methyl ethyl ketone, cyclohexanone, diethylene glycol monomethyl ether, γ-butyrolactone, tetrahydrofuran, methylene chloride, ethylene chloride, dimethyl sulfoxide, dimethyl formamide. etc., and these can be used singly or in combination.
Can be used in combination with more than one species.

The image forming material according to the present invention produced in this manner is first imagewise exposed to actinic light.

Various light sources are used for imagewise exposure, such as an ultra-high pressure mercury lamp, a tungsten lamp, a mercury lamp, a xenon lamp, a fluorescent lamp, a CRT light source, and a laser light source.

The image-forming material imagewise exposed in this way is subjected to a development process to form an image. For example, in the case of two layers, a colored recording layer and a photosensitive layer, the non-image area of the photosensitive layer is removed by treatment with a solvent that does not dissolve the image area but dissolves the non-image area, forming a resist image. Further, by using a developing solution that dissolves or swells the colored recording layer and does not dissolve the resist image on the photosensitive layer, the portion where the photosensitive layer is removed and the colored recording layer is exposed is dissolved or rubbed off. Alternatively, the non-image area of the photosensitive layer and the colored recording layer can be removed by treatment with a solvent that does not dissolve the image area of the photosensitive layer but can dissolve and/or swell both the non-image area of the photosensitive layer and the colored recording layer. The image may be formed by simultaneously dissolving or rubbing off the parts.

In the development of these colored photosensitive layers, the selection of solvents at each stage is important, but the present invention can be carried out by applying conventionally well-known techniques in both cases.

The resulting colored image is then transferred to printing paper such as high-quality paper or art paper. Specifically, the colored image and printing paper are overlapped and passed through a laminator under heat and pressure. The colored image is transferred to the printing paper by heating and pressure during the passage.

When creating a multicolor proof sheet, the above exposure, development, and
A colored image can also be formed on printing paper by repeating the transfer for the required number of colors.

〔Example〕

Examples will be given below, but the present invention is not limited thereto.

<Example 1> A colored photosensitive layer having the following composition was formed on the surface of the polypropylene film of a support in which a 30 μm thick polypropylene film (Tren Anne 3931 manufactured by Toshi Co., Ltd.) was laminated on a 75 μm thick polyethylene terephthalate film by a dry lamination method. The dispersion liquid was coated using a wire bar to give a dry film thickness of 1 μm, and dried to produce colored image forming materials in four colors.

Photosensitive resin having the following structure (A) Novolac resin having the following structure (average molecular weight 1.000) (B) H Ethyl cellosolve (tIC) (Preparation table) Plaque (A') 1.15 (B) 3. 85
(EC) 42.8
Super absorbent resin cyan magenta Xa- 1,151,151,15 3,853,853,85 39,640,640,6 (R material) Carbon black #50 0.99 (
(manufactured by Mitsubishi Kasei) Chrome Phthalref 4GN -0,5
5 (manufactured by Ciba Geigy) Chrome Phthallev F A --0
, 68 (manufactured by Ciba Geigy) Ri U More Taruie 0-8G ---0,
68 (manufactured by Ciba Geigy) The obtained four-color image forming material was overlapped with a color separation positive mask for each color, and 50CI was produced using a 3KW metal halide lamp.
After imagewise exposure from a distance of I+, 5DP-1 (Sakura p
S version developer: 15 times diluted solution of Konishiroku Photo Industry) 30
The film was developed for a few seconds to obtain a four-color image.

Next, the black image was brought into close contact with art paper and passed between a pair of nip rolls heated at 100° C. to transfer the color image onto the art paper. Subsequently, color images were transferred in the order of cyan, magenta, and yellow to obtain a color proofing sheet consisting of four colors on art paper.

The obtained color proof had a 5% increase in the area of the 15OL midpoint of the halftone dot wedge, and obtained a dot gain that was almost the same as that of the actual printing in offset printing, and was very good and very close to the printed material.

<Example 2> In the same manner as in Example 1, a support was prepared by laminating a polypropylene film (Tren Anne 3931 manufactured by Toshi Co., Ltd.) and a polyethylene terephthalate film.

Next, a colored photosensitive layer dispersion having the following composition was coated using a wire bar to a dry film thickness of 1 μm, and dried to prepare colored image forming materials in four colors.

(Liquid preparation table) Black Cyan Magenta Copolymer of 0-benzyl methacrylate and methacrylic acid (BM^/MA 73/27 mol) Pentaerythritol tetra-7 acrylate Michylazuk) Benzophenone para Methoxyphenol methyl securator 0 60 60 60 43.2 43.2 43.2 43.20.41 2.54 0.12 too.

0.41 2.54 0.12 0.41 2.54 0.12 0.41 2.54 0.12 Super absorbent resin black Cyan Magenta Yellow (pigment) Carbon black 150 19.8
- - (Mitsubishi Kasei) Chrome phthalbuto 4GN -11,
0 (manufactured by Ciba Geigy) Chrome 7 Tarref FA --13
, 6 (manufactured by Ciba Geigy) Kuromofukurui xn-8G ---1
3,6 (manufactured by Ciba Geigy) Furthermore, a solution having the following composition was applied as an overcoat layer on the colored angry light layer so that the dry film thickness was 0.3 μm.

Polyvinyl alcohol (Nippon Gohsei GL-05) 60 parts Distilled water 970 parts Methanol
30 copies of the four-color image forming material obtained were superimposed on a color separation negative mask for each color, imagewise exposed from a distance of 503 using a 3:1 metallolide lamp, and then 5DN-21 (Sakura PS plate developer: Konishi) Using a 3-fold diluted solution (manufactured by Rokusha Co., Ltd.) at 35° C. for 20 seconds, development was performed to obtain a four-color image.

Next, the black image was brought into close contact with art paper and passed between a pair of nip rolls heated at 100° C. to transfer the color image onto the art paper. Subsequently, color images were transferred in the order of cyan, magenta, and yellow to obtain a color proofing sheet consisting of four colors on the image-receiving sheet.

The obtained color proof had a 6% increase in the area of the 15OL midpoint of the halftone dot wedge, and the dot gain was almost the same as that of the actual printing in offset printing, and it was very good and very close to the printed matter.

Comparative Example 1> Methylene chloride 113.0g
Methanol 1.6g Methyl methacrylate, ethyl acrylate 5.6g Copolymer of acrylic acid (32158/10 by weight) Molecular weight - 260,000, Tg 37°C Bisphenol A epoxy resin obtained from bisphenol A and epichlorohydrin Diacrylate ester, viscosity 1,000.000 cps UV-reactive oligomer 2-0-chlorophenyl-4,5-bis(phenyl)- obtained from trimethylolpropane triacrylate and hydrogen sulfide
Copolymer of imidazolyl dimer 2-mercaptobenzoxazole ethyl acrylate/acrylic acid (92/8 by weight), molecules 2.5 g 2.9 g 0.2 g 0, 1 g 2.4 g i=7.000 ? -(4'-chloro-6'-diethylamide 0.4
gnor1",3',5°-triazin-4°-yl)-
Amino-3-phenylcoumarin p-methoxyphenol 0.003 g Zinc acetylacetonate (methylene 0.4 g dissolved in a mixture of chloride/methanol 5:lV/V 1zIIItt) A coating solution having the above composition was applied after drying. A polyethylene terephthalate film (12,5μ11) was coated with a polyethylene terephthalate film (12,5μ11) so as to obtain a photopolymerizable film with a thickness of 5μI, then a thickness of 19
A μm transparent polypropylene cover film was laminated onto this.

To obtain a four-color image, this photopolymerizable film was laminated onto an image-receiving material (Kromekote) at the same time as the cover film was removed. This is then passed through a screen gradation and cyan color separation positive with sufficient area to a 3,000 liter metal halide lamp and an ultraviolet filter (Kokomo).
) filter) for 42 seconds at a distance of 95 cm in a vacuum chamber. The polyethylene terephthalate film was then removed and a conventional cyan toner was applied to the exposed side in an automatic toning machine. This toner remains attached only to the unexposed sticky areas of the film.

On the side of this colored material, a second layer of photopolymerizable film is applied.
The layers were laminated, exposed for 47 seconds as before through the corresponding magenta color separation, and colored with a conventional magenta toner. Yellow (exposure time 47 seconds)
The corresponding operating steps were repeated for black and black (exposure time 60 seconds). After applying the final color, a protective film is applied. For this purpose a fifth photopolymerized film was laminated, exposed and the polyethylene terephthalate film was stripped.

Although the obtained color proof had an optical dot gain by covering the entire image with a polymer film, it did not have the same physical dot gain as a printed matter.

〔Effect of the invention〕

As described above, according to the present invention, the obtained transferred image can be made to approximate an actual printed matter.

Claims (1)

[Claims] (1) An image forming material having a colored photosensitive layer containing a photosensitive composition and a colorant on a support is imagewise exposed and developed to form a colored image, which is transferred to a transfer material. A method for forming a transfer image by: A transfer image forming material, characterized in that the colored photosensitive layer contains a highly water-absorbing resin.